The invention relates to a radiation heater, particularly utilizing a gaseous fuel, having a double walled housing of a generally trapezoidal transverse cross-sectional configuration. The housing is defined by lateral or side walls diverging away from a top wall and opposite end walls collectively defining a peripheral edge which defines an opening of the housing. A ceramic plate burner is located between a mixing chamber and a radiation grid. An intermediate chamber houses an injector nozzle and a mixing tube which admixes air and fuel which is fed through the intermediate chamber and a transition chamber into the mixing chamber incident to combustion and the associated generation and radiation of heat.
A radiation heater of the type just described is disclosed in German Patent 30 12 588. The radiation heater of this patent is designed for use in those fields where a radiation heater is exposed to winds of high strengths or storms or very large drafty workplaces or sports arenas in which the individuals/spectators are heated by radiation. In such cases conventional radiation heaters have been found quite adequate. However, substantial design complexity is involved to guard against the adverse effect of high winds or drafts, both at the input side of the combustible air/fuel admixture and on the radiation side of the burner plate from which the hot waste gases discharge. Moreover, a comparatively high operational pressure is required for the fuel/air mixture. Such high operational pressures are required mainly when the radiation heater radiates heat vertically downwardly, and in such cases the prior art dictates the location of the fuel supply, the air supply, the mixing chamber, the injection nozzle and the mixing tube above the burner plate. As a result, a relatively large space, including the mixing chamber, is required inside the burner housing above the burner plate to locate the latter-listed items. Because of this, difficulties arise on the one hand in keeping the fuel/air supply or admixture on the intake side of the burner plate uniform, and on the other hand it is impossible to sufficiently intensely and uniformly preheat the fuel/air admixture--two objectives which are highly desirable. Representative of patents which evidence the design principle of mounting the supply of fuel and air above the burner plate can be found in U.S. Pat. No. 3,434,466; German Auslegeschrift 1,164,059; Swiss Patent No. 359,861; French Patent Application 2,624,253; and German Offenlegungsschrift 28 29 075.